Background <p>The carotid web was first reported by Momose et al. in 1977. Most case reports involve patients under 60 years old; thus, the carotid web is recognized as a potential cause of embolic cerebral infarctions in relatively young patients who lack conventional stroke risk factors and often experience recurrence.</p> Case presentation <p>A woman in her mid-80s presented to our hospital 1 h following aphasia onset and severe right hemiparesis. Magnetic resonance imaging revealed a left middle cerebral artery occlusion; therefore, percutaneous thrombectomy was considered. Digital subtraction angiography (DSA) revealed flow restoration and blood flow stagnation at the downstream surface of the carotid web (CW) niche where thrombi originate. This finding was typical for a CW; however, based on the patient’s age, history of diabetes mellitus, and absence of previous strokes, we initially misinterpreted it as an atherothrombotic plaque with ulceration. Meticulous investigation failed to identify any intra- or extracranial embolic source. Thus, we performed computed tomography angiography (CTA) in oblique-sagittal projections and confirmed the diagnosis; ultrasound and MR angiography provided no diagnostic value, as previously reported. Carotid artery stenting was performed for prevention of the recurrence.</p> Conclusion <p>Patients with a symptomatic carotid web are usually young and have few conventional stroke risk factors. However, a carotid web should not be excluded as the cause of an initial cerebral infarction if the patient is elderly. Typical DSA findings should not be overlooked, and CTA is an important noninvasive imaging modality to avoid a misdiagnosis.</p>